减少图片文件的重复解码提升性能

Author: lindexi

src/MediaConverters/MediaConverters.Lib/Imaging/Optimizations/ImageFileOptimization.cs

@@ -78,32 +78,40 @@ public static async Task<ImageFileOptimizationResult> OptimizeImageFileAsync(Fil
             };
         }
 
-        using var _ = image;
-
-        if (image.Metadata.DecodedImageFormat is GifFormat)
+        try
         {
-            return new ImageFileOptimizationResult()
+            if (image.Metadata.DecodedImageFormat is GifFormat)
             {
-                OptimizedImageFile = null,
-                FailureReason = ImageFileOptimizationFailureReason.NotSupported
-            };
-        }
+                image.Dispose();
+                return new ImageFileOptimizationResult()
+                {
+                    OptimizedImageFile = null,
+                    FailureReason = ImageFileOptimizationFailureReason.NotSupported
+                };
+            }
 
-        OptimizeImage(image, maxImageWidth, maxImageHeight, useAreaSizeLimit);
+            OptimizeImage(image, maxImageWidth, maxImageHeight, useAreaSizeLimit);
 
-        // 重新保存即可
-        var outputImageFilePath = Path.Join(workingFolder.FullName, $"{Path.GetRandomFileName()}.png");
-        await image.SaveAsPngAsync(outputImageFilePath, new PngEncoder()
-        {
-            ColorType = PngColorType.RgbWithAlpha,
-            BitDepth = PngBitDepth.Bit8,
-        });
+            // 重新保存即可
+            var outputImageFilePath = Path.Join(workingFolder.FullName, $"{Path.GetRandomFileName()}.png");
+            await image.SaveAsPngAsync(outputImageFilePath, new PngEncoder()
+            {
+                ColorType = PngColorType.RgbWithAlpha,
+                BitDepth = PngBitDepth.Bit8,
+            });
 
-        return new ImageFileOptimizationResult()
+            return new ImageFileOptimizationResult()
+            {
+                Image = image,
+                OptimizedImageFile = new FileInfo(outputImageFilePath),
+                FailureReason = ImageFileOptimizationFailureReason.Ok
+            };
+        }
+        catch
         {
-            OptimizedImageFile = new FileInfo(outputImageFilePath),
-            FailureReason = ImageFileOptimizationFailureReason.Ok
-        };
+            image.Dispose();
+            throw;
+        }
     }
 
     /// <summary>

src/MediaConverters/MediaConverters.Lib/Imaging/Optimizations/ImageFileOptimizationResult.cs

@@ -2,12 +2,15 @@
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
+
 namespace DotNetCampus.MediaConverters.Imaging.Optimizations;
 
 /// <summary>
 /// 图片文件优化结果
 /// </summary>
-public readonly record struct ImageFileOptimizationResult()
+public readonly record struct ImageFileOptimizationResult() : IDisposable
 {
     /// <summary>
     /// 优化后的图片文件
@@ -17,6 +20,13 @@ public readonly record struct ImageFileOptimizationResult()
     public Exception? Exception { get; init; }
     public ImageFileOptimizationFailureReason FailureReason { get; init; } = ImageFileOptimizationFailureReason.Ok;
 
-    [MemberNotNullWhen(true, nameof(OptimizedImageFile))]
-    public bool IsSuccess => OptimizedImageFile is not null;
+    [MemberNotNullWhen(true, nameof(OptimizedImageFile), nameof(Image))]
+    public bool IsSuccess => OptimizedImageFile is not null && Image is not null;
+
+    public Image<Rgba32>? Image { get; init; }
+
+    public void Dispose()
+    {
+        Image?.Dispose();
+    }
 }

src/MediaConverters/MediaConverters.Tool/Program.cs

@@ -38,7 +38,7 @@ internal static async Task<ErrorCode> RunAsync(Options options)
 
         var workingFolder = Directory.CreateDirectory(options.WorkingFolder);
 
-        var imageFileOptimizationResult = await ImageFileOptimization.OptimizeImageFileAsync(inputFile, workingFolder, imageConvertContext.MaxImageWidth, imageConvertContext.MaxImageHeight, imageConvertContext.UseAreaSizeLimit ?? true);
+       using var imageFileOptimizationResult = await ImageFileOptimization.OptimizeImageFileAsync(inputFile, workingFolder, imageConvertContext.MaxImageWidth, imageConvertContext.MaxImageHeight, imageConvertContext.UseAreaSizeLimit ?? true);
 
         if (!imageFileOptimizationResult.IsSuccess)
         {
@@ -68,7 +68,7 @@ internal static async Task<ErrorCode> RunAsync(Options options)
 
         if (imageConvertContext.ImageConvertTaskList is { } list)
         {
-            using var image = await Image.LoadAsync<Rgba32>(optimizedImageFile.FullName);
+            var image = imageFileOptimizationResult.Image;
             var workerProvider = new WorkerProvider();
 
             foreach (IImageConvertTask imageConvertTask in list)